CSA 1916 New Designs

[Guinness]

Spurred on by the experience of the recent around the world cruise, and by the continued aggressive Colombian building program, in 1916 the CSA will lay down a new class of battleships, the Tennessee class.

Although tempted to answer the Radiantes directly, the CSN eventually decided to request from Congress authorization for two more conservative ships armed with more powerful 15 inch 2000 pounder guns.

Early design drafts had these ships equipped with a secondary armament housed only in gunhouses, similar to the Enterprise class. However, a certain amount of buyers remorse on the decision to abandon casemates in the Enterprises, coupled with a desire to mount a heavier secondary broadside led to the decision to return to casemates for the Tennessees.

Two ships will be laid down in 1916, Tennessee and Sonora.









(Click on each image to view full size)

CSS Tennessee, CSA Battleship laid down 1916 (Engine 1912)

Displacement:
   30,300 t light; 32,081 t standard; 34,226 t normal; 35,943 t full load

Dimensions: Length overall / water x beam x draught
   668.00 ft / 655.00 ft x 104.00 ft x 27.65 ft (normal load)
   203.61 m / 199.64 m x 31.70 m  x 8.43 m

Armament:
      8 - 15.00" / 381 mm guns (4x2 guns), 2,000.00lbs / 907.18kg shells, 1916 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      8 - 5.50" / 140 mm guns (4x2 guns), 75.00lbs / 34.02kg shells, 1916 Model
     Breech loading guns in deck mounts with hoists
     on side, all amidships
      12 - 1.00" / 25.4 mm guns (6x2 guns), 0.50lbs / 0.23kg shells, 1916 Model
     Anti-aircraft guns in deck mounts
     on side, evenly spread, all raised mounts
      2 - 1.58" / 40.0 mm guns in single mounts, 2.00lbs / 0.91kg shells, 1916 Model
     Anti-aircraft guns in deck mounts
     on side, all amidships, all raised mounts - superfiring
      10 - 5.50" / 140 mm guns in single mounts, 75.00lbs / 34.02kg shells, 1916 Model
     Breech loading guns in casemate mounts
     on side, evenly spread
     6 guns in hull casemates - Limited use in heavy seas
   Weight of broadside 17,360 lbs / 7,874 kg
   Shells per gun, main battery: 112

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   13.5" / 343 mm   426.00 ft / 129.84 m   16.00 ft / 4.88 m
   Ends:   Unarmoured
     Main Belt covers 100 % of normal length

   - Torpedo Bulkhead:
      2.50" / 64 mm   426.00 ft / 129.84 m   29.50 ft / 8.99 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   16.0" / 406 mm   7.00" / 178 mm      13.5" / 343 mm
   2nd:   1.50" / 38 mm   1.00" / 25 mm      3.00" / 76 mm
   3rd:   0.50" / 13 mm         -               -
   4th:         -      1.00" / 25 mm            -
   5th:   1.50" / 38 mm         -         3.00" / 76 mm

   - Armour deck: 4.00" / 102 mm, Conning tower: 15.00" / 381 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 53,300 shp / 39,762 Kw = 23.01 kts
   Range 8,352nm at 12.00 kts
   Bunker at max displacement = 3,862 tons

Complement:
   1,257 - 1,635

Cost:
   £4.801 million / $19.203 million

Distribution of weights at normal displacement:
   Armament: 1,876 tons, 5.5 %
   Armour: 12,459 tons, 36.4 %
      - Belts: 4,044 tons, 11.8 %
      - Torpedo bulkhead: 1,162 tons, 3.4 %
      - Armament: 3,100 tons, 9.1 %
      - Armour Deck: 3,812 tons, 11.1 %
      - Conning Tower: 341 tons, 1.0 %
   Machinery: 2,125 tons, 6.2 %
   Hull, fittings & equipment: 13,393 tons, 39.1 %
   Fuel, ammunition & stores: 3,926 tons, 11.5 %
   Miscellaneous weights: 447 tons, 1.3 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     51,960 lbs / 23,569 Kg = 30.8 x 15.0 " / 381 mm shells or 9.5 torpedoes
   Stability (Unstable if below 1.00): 1.12
   Metacentric height 6.5 ft / 2.0 m
   Roll period: 17.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.69
   Seaboat quality  (Average = 1.00): 1.35

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.636
   Length to Beam Ratio: 6.30 : 1
   'Natural speed' for length: 25.59 kts
   Power going to wave formation at top speed: 46 %
   Trim (Max stability = 0, Max steadiness = 100): 52
   Bow angle (Positive = bow angles forward): 24.52 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      28.50 ft / 8.69 m
      - Forecastle (18 %):   25.00 ft / 7.62 m
      - Mid (50 %):      23.25 ft / 7.09 m (15.50 ft / 4.72 m aft of break)
      - Quarterdeck (18 %):   15.50 ft / 4.72 m
      - Stern:      15.50 ft / 4.72 m
      - Average freeboard:   20.19 ft / 6.15 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 79.3 %
      - Above water (accommodation/working, high = better): 154.4 %
   Waterplane Area: 51,516 Square feet or 4,786 Square metres
   Displacement factor (Displacement / loading): 106 %
   Structure weight / hull surface area: 197 lbs/sq ft or 963 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.96
      - Longitudinal: 1.38
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is excellent
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

Misc Weights:
250 t Fire Control
25 t Marconi
25 t Marconi
50 t Flag Facilities
97t: Reserve

Endurance: 5532 miles at 12 knots + 1 day at top speed

[The Rock Doctor]

The Colombian building program is assertive, not aggressive.

Nice design - in many respects, a better design than the Radiantes.

[P3D]

Your picture shows a much more streamlined ship than the SS2 suggest (BC= 0.636). I can even make some calculations about surface area based on the pic...

I'd suggest a much broader and rounded stern on the top view.

[Guinness]

See that's funny, because the entire time I was thinking to myself "it looks too fat". Of course, that's the difficulty of illustrating these without doing actual hull design. I'd gone off top views of the US standards in Friedman.

How far off is it? I could also monkey with giving her a longer "parallel" midships section too I suppose.

[P3D]

Apparently not THAT far off as I though first. 5-10% at most counting sheer and whatever (51500sqft ss2 waterplane area vs. 50700sqft deck area). So don't bother.

[Carthaginian]

A better question, for those of us that do not know how, is exactly how do ya'll figure such things up? It would help me a mighty good bit if I knew how to figure that out; then, I could try some top-down drawings at least for my own info.

[Guinness]

Apparently not THAT far off as I though first. 5-10% at most counting sheer and whatever (51500sqft ss2 waterplane area vs. 50700sqft deck area). So don't bother.

Woohoo! :)

Actually, there's a couple of other detail things I'm fixing (I forgot a bunch of ventilation facilities), so I may just round off the stern a little more while I'm in there.

At least I got a bit closer on this one then with the Enterprises.

[P3D]

A better question, for those of us that do not know how, is exactly how do ya'll figure such things up? It would help me a mighty good bit if I knew how to figure that out; then, I could try some top-down drawings at least for my own info.

Edit the top view in Paint. Background set to white. I save it as a moconchrome BMP, fill in the white areas with black, then save as 256-color BMP.

I load the pic with 'Image J' (free image analysis software) and it would count black pixels (intensity 0, or total pixels minus white ones) - with the Histogram function it is one click. In this case 202852 pixel for the deck area, divide by 4 (2pixel/ft) and I get 50714sqft deck area.

[Carthaginian]

What I mean, is how would we use the block coefficient to get a rough idea of how to wide to make the ship over what percentage of it's length, P3D.

I appreciate the explanation you gave, but unfortunately, it's a little harder for me to grasp than, say, Syrian Aramaic. :-[ I will give the program you mention a look and see if I can make sense out of it when I have the proper materials to work with. ;)

[P3D]

It is the "waterplane area" which matters not the BC - the latter is 3D and it would be difficult to use it in any quantitative way.

So you have to determine the area of the top view and compare it to the SS2 values. What I wrote is a method to do this.

[The Rock Doctor]

Lovely drawing, incidently.  If I ever have to sink them, I will surely shed a tear.

[Guinness]

I gave her just a little more junk in the trunk, so to say. The area of the hull as rendered is now 52216 sq feet, which is just a little bit more than the SS2 waterplane area. This is probably about right, as she does have a little bit of flare forward.

Lovely drawing, incidently.  If I ever have to sink them, I will surely shed a tear.

I'm sure the Colombians would surely weep at vanquishing such a worthy adversary.